I came across a hobby of collecting and analysing sand while looking for a website on a totally unrelated subject. Sand is defined as a substance where 50% of the material will no pass thru a sieve of 0.075mm diameter, but will pass thru a sieve of 4.75mm. Anything larger than 4.75mm is gravel and something to be avoided at all costs.
You can look at sand thru some relatively low power microscopes 10x – 40x should be sufficient. Most beaches can be identified by their sand. In Guam there is a beach with green sand, which has been formed by the erosion of olivine crystals, which have come from a nearby lava cone. So where does sand come from, other than the green stuff. Well it comes from rocks, shells, skeletal fragments from sea animals and pretty much anything else which will erode over time.
Beach sand like Poppit Sands normally has smooth grains due to the waves producing constant motion and the sand dunes are constantly being blown around creating a similar effect.
For lots more information on collecting sand and other related topics here are a few websites.
The International Sands Collectors Society
Sand collectors are apparently up for swapping sand samples, so why not register on one of their sites –
For further articles please visit Poppit Sands Holiday Cottage